1. Field of the Invention
The invention relates to a process for the reproduction of oil paintings and the like with a relief surface, using a relief mold taken from the original and a thermoplastic foil imprinted with the color picture representing the original, which is formed while being heated.
2. Description of the Prior Art
In order to reproduce, for instance, an oil painting, such may be copied. Good copies, however, demand such a high degree of skill and so much time that they are very expensive and cannot be produced to meet increased demands and increasing living standards. While artistic polychrome prints permit very high fidelity in color and shading and are inexpensive, they include the disadvantage of lacking the relief dimensions of the original, which in an oil painting or a similar artistic art object is also a means of expression of the artist and is recognized as such by the layman.
As a solution of this problem DEPS No. 494, 894; FR-PS No. 15 21 466; DE-AS No. 20 19 699 and DE-OS No. 2 352 966 disclose processes by means of which a transparent layer of gelatine or plastic, respectively, is applied to a polychrome print of the original which, by means of a mold taken from the original is given the relief texture of the surface either before or after its application to the picture surface. In this manner, the transparent surface mimicks the relief character of the surface structure, but still does not have the same effect as the original, since the surface structure is not created by the color so that the effect of this surface structure very highly depends on the viewing angle, the lighting and similar influences.
These inadequacies are prevented when using the process as described in the category of processes of the present invention or as described in FR-PS No. 14 93 516, as well as in FR-PS No. 15 48 337. According to FR-PS No. 14 93 516 the relief mold is supplied with openings for air passage. Then, the printed foil is superimposed on the relief mold in a fitting alignment, and a thick polystyrene foil is applied. The polystyrene foil is then heated to the softening temperature of the printed foil. Then, by means of a partial vacuum beneath the relief mold and/or excess pressure above the polystyrene foil, the latter is pressed into the indentations of the relief mold together with the printed foil. In this manner, after hardening, the printed foil has the surface structure of the original.
The process according to FR-PS No. 15 48 337 is identical to the process just described with the exception that the printed foil is heated by means of infra-red radiation instead of contact heating by means of a polystyrene foil and that molding takes place exclusively by a partial vacuum beneath the relief mold. This represents an improvement over the above mentioned transparent relief surface layers. Inasmuch, however, as with both of these processes considerable pressure forces act upon the foil during the molding, such force being listed as 7 kg/cm.sup.2 for the first described process, it follows that the foil must necessarily have a certain thickness. As a consequence, delicate relief structures may not be reproduced with great fidelity. While this may not be very important for some types of originals, the delicate technique of mannerism, especially of the Munich school, will result in marked differences from the original.